lacunary - Mathnotes

Fundamental Theorem of Calculus

Fundamental Theorem of Calculus: If f is Riemann integrable on [a,b] and F is a function on [a,b] for which F′(x)=f(x) for all x∈[a,b], then

∫abf(x)dx=F(b)−F(a).

Derivative Part of the Fundamental Theorem: Let f be continuous on [a,b] and define the function F on [a,b] by

F(x)=∫abf(y)dy.

Then, F is continuous on [a,b], and for all x∈(a,b), F is differentiable and F′(x)=f(x).

Integration by Parts Theorem: Let f and g be continuously differentiable functions on [a,b]. Then

∫abf(x)g′(x)dx=f(b)g(b)−f(a)g(a)−∫abf′(x)g(x)dx.

Substitution Theorem for Integration: Let g be a function with a continuous derivative on [a,b]. If f is continuous on the range of g, then

∫abf(g(x))g′(x)dx=∫g(a)g(b)f(u)du.